In order to continuously improve performance of super large-scale integrated circuits, a feature size of a complementary metal oxide semiconductor (CMOS) device decreases continuously. However, when the size of the device decreases to deep sub-micron, a short-channel effect (SCE) on a sub-threshold characteristic and the like is more obvious, which has become a main bottleneck that limits a decrease of the size of the device. In view of the foregoing problem, not only a new structure and a new material may be used to inhibit an SCE of a metal oxide semiconductor field effect transistor (MOSFET), an impact on the SCE may also be reduced by changing a working mechanism of the MOSFET, for example, a tunneling field effect transistor (TFET). Because injection of carriers at a source end of the TFET is based on a tunneling mechanism, a smaller subthreshold swing (SS) can be obtained, thereby satisfying a low power consumption application. In addition, because of a change in an injection manner of the carriers at the source end, the TFET can exhibit a better short-channel effect inhibiting capability, which facilitates improving an integration level of the device, and reducing production costs.
In the prior art, on the one hand, as shown in FIG. 1, a part of a tunneling region 60 is added between a source 10 and a gate dielectric layer 40, thereby increasing a tunneling area to increase a tunneling current. However, there is a limitation to the tunneling area of a TFET with this structure, and if the tunneling area needs to be increased, an integration area or an SS value of the transistor may increase. On the other hand, as shown in FIG. 2, a new electric field is combined by controlling an epitaxial layer and a multi-gate structure, thereby increasing an electron tunneling probability to increase a tunneling current. Although a tunneling probability of a TFET with this structure is increased, a tunneling area is not large. If the tunneling area needs to be increased, an increase of an integration area or an increase of an SS value of the transistor is caused.